1.8 - Changing pathogens

Question 1

Why do some pathogens spread rapidly?

Answer 1

• Some pathogens, particularly viruses, can mutate, resulting in a mutation
• Very few people are immune to these so disease can spread very quickly

Question 2

What is the name of a disease that spreads within a country?

Answer 2

An epidemic

Question 3

What is the name of a disease that spreads across countries?

Answer 3

A pandemic

Question 4

How has the MRSA ‘superbug’ evolved?

Answer 4

Through natural selection

Question 5

What can mutated pathogens, like MRSA, become immune to?

Answer 5

Common antibiotics

Question 6

How does natural selection cause resistant populations of bacteria to develop?

Answer 6

• Mutations of pathogens produce new strains, some of which are resistant to antibiotics
• Antibiotics kill pathogens of the non-resistant strain
• The resistant bacteria survive and reproduce (natural selection)
• A whole population of a resistant strain develops

Question 7

How can we slow the development of resistant strains of bacteria?

Answer 7

We should not use antibiotics for mild infections